Diffusion and/or filtration apparatus

ABSTRACT

The present invention relates to a diffusion and/or filtration apparatus, including a housing which consists of a cylindrical open-ended main part closed by two end caps and provided with an inlet and an outlet for a fluid. This fluid is adapted to flow through the fibers of a bundle of semipermeable hollow fibers which are arranged between two end walls within the housing. Additionally, the housing includes at least a second outlet for another fluid, with this fluid being adapted to be removed from the space outside the fibers through this second outlet, the ends of the hollow fibers being moulded into the end walls of the housing and opened by a cutting.

FIELD OF THE INVENTION

The present invention relates to diffusion and/or filtration apparatus.More particularly, the present invention relates to such apparatus whichincludes a housing with a cylindrical open-ended main housing with abundle of semi-permeable hollow fibers with end caps providing inletsand outlets for a first fluid which flow through the fibers and at leastone other outlet for a second fluid which is withdrawn for the spacebetween the fibers and the housing. Still more particularly, the presentinvention relates to methods of manufacturing such diffusion and/orfiltration apparatus.

BACKGROUND OF THE INVENTION

Diffusion/filtration devices are used for various kinds of medicaltreatments, such as hemodialysis, hemofiltration, plasmapheresis andimmunotherapy. Other fields of use include, inter alia, dialysis ingeneral and filtration in general, for example in connection with thecleaning or desalination of sea water.

During the production of such diffusion/filtration devices each end ofthe housing, with a bundle of fibers therein, is normally enclosed in acasting mould into which the potting material for the adjacent end wallsis fed in a liquid condition penetrating into and around the fibers. Thepenetration is controlled by the casting so that the penetration intothe fibers is less than that around the fibers, making it possible toopen the ends of the fibers by making a cut between the respectivepenetration depths.

These penetration depths may be controlled in different ways.Preferably, though, it is controlled in accordance with the methoddescribed and claimed in EP-B-O 165 478. Thus, the wall material may befed into the device as described in the above European patent or, in thealternative, through the other two normally existing inlets/outlets asdescribed in U.S. Pat. Nos. 4,227,295 or 4,329,229. In both cases,though, the wall material is firmly attached to the inside wall of thehousing.

As a result, during the curing of the wall material, stresses developwhich sometimes result in unacceptable cracks in the wall or thehousing. Such cracks may for instance be created in connection with theopening of the fiber ends, the flushing of the apparatus or thesterilization of the completed apparatus.

An attempt to solve the above problem is described and claimed in U.S.Pat. No. 4,334,993. The present invention provides an alternative andnovel solution for the same problem. Furthermore, the present inventionprovides additional advantages as described below.

SUMMARY OF THE INVENTION

The present invention relates to a diffusion and/or filtration apparatusof the kind defined above. This apparatus is characterized by thestrength of the attachment between the moulded end walls and the housingbeing reduced or substantially eliminated by a ring which has a lowadhesive capacity in relation to the material of the end walls.Additionally, in accordance with this invention, the end walls are alsosupported in the longitudinal direction of the housing.

Specifically, the present invention provides a housing that defines alongitudinally extending internal chamber which includes a first end anda second end. A bundle of semipermeable hollow fibers are disposedwithin the internal chamber. Accordingly, the hollow fibers extendlongitudinally from the first end of the housing to the second end ofthe housing and therefore, have their own first and second end. Thesehollow fibers additionally have an outer surface.

Disposed between the bundle of hollow fibers and the housing is an endwall. This end wall sealingly separates the first and second ends of thehollow fibers from the outer surface of those hollow fibers.

Disposed at the first end of the housing is a first inlet. Disposed atthe second end of the housing is a first outlet. Additionally, a secondoutlet is provided for the evacuation of fluid from the internal chamberof the housing at a point between the first and second ends of thehousing.

Interposed between the end wall and the housing is a ring member. Thisring member has a shape that corresponds to the housing and defines acavity between itself and the hollow fibers. This ring member has acoefficient of adhesion in relation to the end wall which is lower thanthe coefficient of adhesion in relation to the housing. As a result, thestructural integrity of the housing and the seal created by the end wallis enhanced and the risk of cracks therein is substantially eliminated.

As a result of the above defined structural integrity, adiffusion/filtration appartus in accordance with the present inventionmay even be heat sterilized (such as by means of a method according toU.S. Pat. No. 4,609,728) in dry condition, if suitable materials arechosen in light of the requirements involved. From the followingdescription, it will be seen that an effective seal between the twofluids involved is also provided.

Additionally, longitudinal support of the end walls is preferablyprovided by a flange arranged on the ring. Such a flange may, forexample, be arranged on the inside of the ring penetrating into theperiphery of the end walls. Such construction may also be used forsupporting the fiber bundle before the casting of the end walls. In thealternative, the ring may have include a protuberance which provides asupport for the bundle of hollow fibers, especially before the moldingof the end walls.

The ring may be supported in the longitudinal direction by the housing,preferably by being arranged in a groove in the inside wall of thehousing.

This ring is also preferably extended outside of the housing prior tothe cutting, in order to serve as a part of the mold for the pottingmaterial which will make up the end walls. This extended portion is cuttogether with the fibers in connection with the opening of the fiberends.

In a preferred embodiment of the apparatus according to the instantinvention, a second ring may be arranged at the outer end surfaces ofthe end walls which will result in a groove in each of the end surfaces.As with the other ring member, this ring has a low adhesive capacity inrelation to the material of the end walls.

Alternatively, the longitudinal support of the ring may be provided bythe housing itself, in that longitudinally extending tongues which areintegral with the housing are partly moulded into the end walls. By sucha construction the ring may be given a very simple form.

The present invention also relates to a method of manufacturing anapparatus as described above. This method includes a bundle ofsemipermeable hollow fibers being arranged in the cylindrical open endedmain part of a housing, with the hollow fibers being supported by a ringhaving a low adhesive capacity in relation to the material of the endwalls. This ring extends beyond the open ends of the hollow fibers andserves as an inlet and/or outlet for a flushing fluid for the flushingof the inside and the outside of the fibers. Additionally, the ring isthereafter used as a part of a mold for the introduction of a pottingmaterial that will form end walls. Thereafter, the housing, the fibersand the end walls are cut transverse the longitudinal orientation of thefibers and the housing in order to open the fiber ends, whereupon theapparatus finally is provided with end caps.

Specifically, the method of manufacture of the instant inventioncomprises the steps of providing a bundle of semipermeable hollowfibers. This bundle of hollow fibers has a first end and a second end. Ahousing which defines a longitudinally extending internal chamber thatincludes a first end and a second end and first outlet means for theevacuation of the internal chamber is also provided. The bundle ofhollow fibers is then inserted into the internal chamber of the housing.

A ring member is also provided. This ring member is inserted into theinternal chamber and over the hollow fibers. Further, this ring memberas thus applied includes a portion that extends beyond the hollow fibersand thus forms an inlet.

A predetermined quantity of a potting material which has a lowercoefficient of adhesion in relation to the ring member than itscoefficient of its adhesion in relation to the housing, is thenintroduced through the inlet defined by the ring member. This pottingmaterial is allowed to penetrate to a predetermined depth of theinternal chamber. As a result, the potting material seals the internalchamber from the ends of the housing and the ends of the hollow fibers.The housing, the ring member, and the hollow fibers are then cuttransverse to the longitudinal line as defined by the internal chamber.This cut is made at a predetermined point between the inlet and thedepth of penetration of the potting material. Lids are then attached tothe first and seconds ends of the housing.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a partial, side, elevational, partially sectional view of adiffusion and/or filtration apparatus of the present invention at afirst stage of its manufacture;

FIG. 2 is a partial, side, elevational, partially sectional view of theapparatus of FIG. 1 at a second stage of its manufacture;

FIG. 3 is a partial, side, elevational, partially sectional view of theapparatus of FIG. 2 at a final state of its manufacture;

FIG. 4 is a partial, side, elevational, partially sectional view ofanother diffusion and/or filtration apparatus of the present inventionat a first stage of its manufacture;

FIG. 5 is a partial, side, elevational, partially sectional view of theapparatus of FIG. 4 at a second stage of its manufacture;

FIG. 6 is a partial, side, elevational, partially sectional view of theappratus of FIG. 4 at a final stage of its manufacture;

FIG. 7 is a partial, side, elevational, partially sectional view ofanother diffusion and/or filtration apparatus of the present inventionat a first stage of its manufacture;

FIG. 8 is a partial, side, elevational, partially sectional view of theapparatus of FIG. 7 in a second stage of its manufacture;

FIG. 9 is a partial, side, elevational view of a portion of theapparatus of FIG. 7 in a final stage of its manufacture; and

FIG. 9a is inlayed, a partial, side, elevational, sectional view of aportion of the apparatus of FIG. 9.

DETAILED DESCRIPTION

Referring to the figures, in which like reference numerals refer to likeportions thereof, FIGS. 1 through 3 depict one end of an apparatusaccording to the present invention during three different phases of itsmanufacture.

In FIG. 1, a bundle of hollow fibers 1 is shown in a housing 2 prior tothe casting of the end walls 3, (shown in FIGS. 2 and 3). The housing isprovided with an inlet and/or outlet 4 which is intended for a firstfluid. A similar inlet and/or outlet may be arranged at the other end ofthe device (not shown). The bundle of hollow fibers 1 is supported by anarrow portion 5 of ring 6 which is arranged in an expanded part 7 ofthe housing 2. The ring 6 is engaged in a groove 8 in the expanded part7 of the housing 2. The ring 6 is provided with an inwardly extendingflange 9 which is shown to reach to a point near the bundle of hollowfibers. Alternatively, it may reach up to the outermost hollow fibers inorder to provide a secondary support for the bundle.

The ring 6 has, as mentioned above, a low coefficient of adhesion inrelation to the material of the end walls 3. It may for instance be madeof polypropylene when the end walls are made of polyurethane, which is amaterial commonly used for such end walls. Alternatively, the ring 6 maybe made of polyethylene, preferably low density polyethylene (LDPE), amaterial which is easier to cut, or Teflon (polytetrafluorethylene), amaterial having a very low adhesive capacity as regards most othermaterials.

In FIG. 2, a mold 10 has been provided. Thus, ring 6 has been connectedto a lid 11, having an inlet 12 for the end wall potting material.

Referring next to FIG. 3, end surface 13 has been created bytransversively cutting through the bundle of hollow fibers 1, thehousing 2, the end wall 3, and the ring 6. The apparatus has thereafterbeen provided with a lid 14 with an inlet and/or outlet 15 intended fora second fluid which may be fed through the fibers to a similar inletand/or outlet 15 arranged at the opposite end of the apparatus (notshown).

Due to the relationship between the material of the end wall 3 and thering 6, a small gap 16 has been provided therebetween. A sealing ring 17has therefore been provided between the lid 14 and the end surface 13 inorder to provide an effective seal between the two fluids involved,i.e., the fluids inside and outside the hollow fibers. It is to beobserved that the gap 16 is not necessary. In practice, it is sufficientto reduce the degree of attachment between the end wall 3 and the ring6. In order to prevent leakage, the lid 14 is preferably tightly weldedto the outer surface of the expanded part 7 of the housing. Othermethods of sealings are acceptable.

FIGS. 4 through 6 show a second embodiment of the apparatus according tothe present invention. Many details are identical or similar to thoseshown in FIGS. 1 through 3, and have therefore been given the samereference numerals, but with the addition of an a.

Consequently, the apparatus as shown is made up of a bundle of hollowfibers 1a in a housing 2a having an expanded part 7a. In a groove 8a inthe expanded part 7a, a slightly modified ring 6a is inserted. Ring 6a,as the previously described ring 6, is provided with a restricted part5a supporting the bundle of hollow fibers 1a. Similarly, an inlet 4acorresponds to the previously described inlet 4.

The main difference between the embodiment according to FIGS. 4 through6 and the above described embodiment, is a number of fingers or tongues18a arranged in the expanded part 7a of the housing 2a. These fingers ortongues 18a are integral extensions of the inner wall of the housing 2a.

Referring next to FIG. 5, the ring 6a has been completed with a lid 11a,which includes an opening 12a for the casting material which make up theend walls 3a. The fingers or tongues 18a are, as can be seen in thisfigure, partly embedded in the end walls 3a. Thus, the tongues 18aprovide support for the end walls 3a in the longitudinal direction ofthe housing 2a.

In FIG. 6 the bundle of hollow fibers 1a, the end wall 3a, the ring 6aand the expanded part 7a of the housing 2a have been transversely cut,providing an end surface 13a. The apparatus has furthermore beenprovided with a lid 14a with an inlet and/or outlet 15a and a sealingring 17a.

FIGS. 7 through 9 and 9a show a preferred third embodiment of theapparatus according to the present invention. Many of the details shownare idential to or similar to the details of FIGS. 1 through 6 and havetherefore been given the same reference numerals, but with the additionof b.

Accordingly, a bundle of hollow fibers 1b is arranged in a housing 2bprovided with an expanded part 7b with an inlet and/or outlet 4b. Afirst ring 6b, similar to the ring 6 previously described, is arrangedin a groove 8b in the expanded part 7b of the housing 2b. The ring 6b isprovided with an inner flange 9b.

The main difference between the embodiment described in FIGS. 7 through9 and 9a, and the embodiment shown in FIGS. 1 through 3, is a secondring 19b arranged partly outside the expanded part 7b of the housing 2b.Said second ring 19b is provided with a restricted part 5b whichcorresponds to the part 5 of the ring 6, and additionally, an innerlongitudinal extending flange 20b which is intended to be partlyembedded in the end wall 3b.

In FIG. 8, the ring 19b has been provided with a lid 11b which includesan opening 12b for the feeding of the casting material for the end walls3b.

In FIG. 9, and the enlargement of a portion of the housing 2b, shown inFIG. 9a, the expanded part 7b of the housing 2b, the end wall 3b, theflange 20b and bundle of hollow fibers 1b, have been cut through, thusproviding an end surface 13b. The apparatus has thereafter been providedwith a lid 14b, which includes an opening 15b, and with a sealing ring17b as described above.

Due to the fact that the ring 6b does not extend up to the end surface13b, the material of the end wall 3b therefore attaches to the inside ofthe expanded part 7b of the housing 2b. This attachment provides a sealbetween the end of the housing 2b and the internal chamber of thehousing. Therefore, the lid 14b does not have to be tightly attached tothe outside wall of the expanded part 7b of the housing 2b. It may forinstance, be attached to the housing 2b by means of a thread arrangedbetween the lid 14b and the expanded part 7b.

The present invention also relates to a method of manufacturing adiffusion and/or filtration apparatus in accordance with the presentinvention. Specifically, referring to FIGS. 1 through 3, a housing 2 isprovided which consists of a cylindrical open ended main part, closed bytwo end caps 14 and being provided with an inlet 15 and an outlet (notshown) for a first fluid and at least one additional outlet 4 for asecond fluid. The first fluid is adapted to flow through the fibers 1 ofa bundle of semi-permeable hollow fibers arranged between two end walls3 within the housing 2, and the second fluid is adapted to be removedfrom the space outside the fibers through the additional outlet 4. Theends of the hollow fibers 1 are moulded into the end walls 3 and openedby transversely cutting same.

The method according to the invention includes the steps of arranging abundle of semipermeable hollow fibers 1 in the cylindrical open endedmain part of the housing 2. A ring 6 which has a low adhesive capacityin relation to the material of the end walls 3 is provided, and extendsoutside the open ends of the hollow fibers 1, and serves as an inletand/or outlet for a flushing fluid for the flushing of the inside andthe outside of the fibers 1. Additionally, ring 6 is thereafter used asa part of a mold for molding the end walls 3. Subsequently, the entirestructure is cut in order to open the fiber ends, whereupon theapparatus finally is provided with end caps 14. Such may also includethe additional steps as set forth in copending U.S. patent applicationNo. 07/565,032.

Specifically, manufacturing such a diffusion/filtration apparatuscomprises the steps of:

Providing a bundle of semi-permeable hollow fibers, the bundle of hollowfibers having a first end and a second end; providing a housing whichdefines a longitudinally extending internal chamber including a firstopen end and a second open end; inserting the bundle of hollow fibersinto the internal chamber; providing a first ring member and insertingthe ring member into at least one of the first and second open ends ofthe internal chamber between the housing and the bundle of hollowfibers; and providing a second ring member and affixing the second ringmember to the housing. This second ring member extends beyond the hollowfibers and forms an inlet, and includes a longitudinally extendingsurface which extends a predetermined distance within the internalchamber between the housing and the hollow fibers. A predeterminedquantity of a potting material, which when set has a lower coefficientof adhesion with respect to the housing means, is then inserted into thefirst and second open ends of the housing so as to penetrate into theinternal chamber a first predetermined distance and into the hollowfibers a second predetermined distance. In this manner, the pottingmaterial seals the internal chamber from the ends of the hollow fibers.The housing, the first ring member, the second ring member and thehollow fibers are then cut transverse to the internal chamber at apredetermined point between the first and second predetermined distancesso as to open the hollow fibers and provide an end wall supporting theends of the hollow fibers. Lid means are then attached over the firstand second ends of the housing.

All the above described figures show one end of the apparatus accordingto the invention. Normally the opposite end is identical to the endshown in the drawings. This is true when, for example, the apparatus isintended to be used for dialysis; a treatment which needs an inlet, aswell as an outlet, for the dialysis liquid. If, however, the apparatusis intended to be used for filtration only, it is enough to have onlyone outlet for the filtrate.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

We claim:
 1. A diffusion/filtration apparatus comprising:a) housingmeans, said housing means defining a longitudinally extending internalchamber including a first end and a second end; b) a bundle ofsemi-permeable hollow fibers disposed within said internal chamber, saidhollow fibers extending longitudinally from said first end of saidhousing to said second end of said housing, said hollow fibers having anouter surface, and a first end and a second end corresponding to saidfirst end and said second end of said internal chamber; c) end wallmeans supporting said first and second ends of said hollow fibers withinsaid internal chamber so as to sealingly separate said first and secondends of said hollow fiber from said outer surface of said hollow fiberbetween said first and second ends thereof; d) first inlet means for theintroduction of a fluid into said first end of said housing means; e)first outlet means for the evacuation of a fluid from said second end ofsaid housing means; f) second outlet means for the evacuation of a fluidfrom said internal chamber at a location between said first and secondend of said housing means; g) at least one ring member disposed betweensaid end wall means and said housing means at one of said first andsecond ends of said internal chamber, said ring member being in directcontact with said housing and having a shape corresponding to saidhousing and defining a cavity between said ring member and said hollowfibers, the coefficient of adhesion between said end wall means and saidring member being lower than the coefficient of adhesion between saidend wall means and said housing, whereby the structural integrity ofsaid housing means and the seal between said ends of said hollow fibersand said outer surface of said hollow fibers is enhanced; and h) atleast one sealing ring interposed between said end wall and said firstinlet means.
 2. The apparatus according to claim 1 including supportmeans within said cavity for longitudinally supporting said end wallmeans.
 3. The apparatus according to claim 2 wherein said ring memberincludes an inner surface and an outer surface, and wherein said supportmeans comprise a flange extending inwardly from said inner surface ofsaid ring member.
 4. The apparatus according to claim 3 wherein saidflange extends inwardly as to said bundle of hollow fibers so as toprovide support therefor.
 5. The apparatus according to claim 2 whereinsaid support means are integral with said housing.
 6. The apparatusaccording to claim 5 wherein said support means comprise longitudinallyextending tongue means extending from a predetermined location on saidhousing means between said first and second ends thereof into said endwall means.
 7. The apparatus according to claim 2 including ring supportmeans for supporting said ring member from said housing.
 8. Theapparatus according to claim 7 wherein said ring support means comprisesan annular groove in said housing, said ring member being longitudinallyengaged in said annular groove.
 9. The apparatus according to claim 7wherein said ring member includes an inner surface and an outer surface,and wherein said support means comprises a flange extending inwardlyfrom said inner surface of said ring member.
 10. The apparatus accordingto claim 1 wherein said first inlet means is defined by a first end capcovering said first end of said housing and said first outlet means isdefined by a second end cap covering said second end of said housing.11. The apparatus according to claim 10 wherein said first and secondend caps are applied to said first and second ends of said housing by ameans selected from the group consisting of welding and gluing.
 12. Adiffusion/filtration apparatus comprising:a) housing means, said housingmeans defining a longitudinally extending internal chamber including afirst end and a second end; b) a bundle of semi-permeable hollow fibersdisposed within said internal chamber, said hollow fibers extendinglongitudinally from said first end of said housing to said second end ofsaid housing, said hollow fibers having an outer surface, and a firstend and a second end corresponding to said first end and said second endof said internal chamber; c) end wall means supporting said first andsecond ends of said hollow fibers within said internal chamber so as tosealingly separate said first and second ends of said hollow fiber fromsaid outer surface of said hollow fiber between said first and secondends thereof; d) first inlet means for the introduction of a fluid intosaid first end of said housing means, said first inlet means beingdefined by a first end cap covering said first end of said housing; e)first outlet means for the evacuation of a fluid from said second end ofsaid housing means, said first outlet means being defined by a secondend cap covering said second end of said housing, said first and secondend caps being applied to said first and second ends of said housing ina fluid-tight manner; f) second outlet means for the evacuation of afluid from said internal chamber at a location between said first andsecond end of said housing means; and g) at least one ring memberdisposed between said end wall means and said housing means at one ofsaid first and second ends of said internal chamber, said ring memberbeing in direct contact with said housing and having a shapecorresponding to said housing and defining a cavity between said ringmember and said hollow fibers, the coefficient of adhesion between saidend wall means and said ring member being lower than the coefficient ofadhesion between said end wall means and said housing, whereby thestructural integrity of said housing means and the seal between saidends of said hollow fibers and said outer surface of said hollow fibersis enhanced.
 13. The apparatus according to claim 12 including supportmeans within said cavity for longitudinally supporting said end wallmeans.
 14. The apparatus according to claim 13 wherein said ring memberincludes an inner surface and an outer surface, and wherein said supportmeans comprise a flange extending inwardly from said inner surface ofsaid ring member.
 15. The apparatus according to claim 14 wherein saidflange extends inwardly as to said bundle of hollow fibers so as toprovide support therefor.
 16. The apparatus according to claim 13wherein said support means are integral with said housing.
 17. Theapparatus according to claim 16 wherein said support means compriselongitudinally extending tongue means extending from a predeterminedlocation on said housing means between said first and second endsthereof into said end wall means.
 18. The apparatus according to claim13 including ring support means for supporting said ring member fromsaid housing.
 19. The apparatus according to claim 18 wherein said ringsupport means comprises an annular groove in said housing, said ringmember being longitudinally engaged in said annular groove.
 20. Theapparatus according to claim 12 including at least one sealing ringinterposed between said end wall and said first inlet means.
 21. Adiffusion/filtration apparatus comprising:a) housing means, said housingmeans defining a longitudinally extending internal chamber including afirst end and a second end; b) a bundle of semi-permeable hollow fibersdisposed within said internal chamber, said hollow fibers extendinglongitudinally from said first end of said housing to said second end ofsaid housing, said hollow fibers having an outer surface, and a firstend and a second end corresponding to said first end and said second endof said internal chamber; c) end wall means supporting said first andsecond ends of said hollow fibers within said internal chamber so as tosealingly separate said first and second ends of said hollow fiber fromsaid outer surface of said hollow fiber between said first and secondends thereof; d) first inlet means for the introduction of a fluid intosaid first end of said housing means; e) first outlet means for theevacuation of a fluid from said second end of said housing means; f)second outlet means for the evacuation of a fluid from said internalchamber at a location between said first and second end of said housingmeans; and g) at least one ring member disposed between said end wallmeans and said housing means at one of said first and second ends ofsaid internal chamber, so as to prevent contact between said end wallmeans and said housing means, said ring member having a shapecorresponding to said housing and defining a cavity between said ringmember and said hollow fibers, the coefficient of adhesion between saidend wall means and said ring member being lower than the coefficient ofadhesion between said end wall means and said housing, whereby thestructural integrity of said housing means and the seal between saidends of said hollow fibers and said outer surface of said hollow fibersis enhanced.
 22. The apparatus according to claim 21, including supportmeans within said cavity for longitudinally supporting said end wallmeans.
 23. The apparatus according to claim 22 wherein said supportmeans are integral with said housing.
 24. The apparatus according toclaim 23 wherein said support means comprise longitudinally extendingtongue means extending from a predetermined location on said housingmeans between said first and second ends thereof into said end wallmeans.
 25. The apparatus according to claim 22 including ring supportmeans for supporting said ring member from said housing.
 26. Theapparatus according to claim 25 wherein said ring support meanscomprises an annular groove in said housing, said ring member beinglongitudinally engaged in said annular groove.
 27. The apparatusaccording to claim 25 wherein said ring member includes an inner surfaceand an outer surface, and wherein said support means comprises a flangeextending inwardly from said inner surface of said ring member.
 28. Theapparatus according to claim 27 including at least one sealing ringinterposed between said end wall and said first inlet means.
 29. Theapparatus according to claim 21 wherein said ring member includes aninner surface and an outer surface, and wherein said support meanscomprise a flange extending inwardly from said inner surface of saidring member.
 30. The apparatus according to claim 29 wherein said flangeextends inwardly as to said bundle of hollow fibers so as to providesupport therefor.
 31. The apparatus according to claim 21 wherein saidfirst inlet means is defined by a first end cap covering said first endof said housing and said first outlet means is defined by a second endcap covering said second end of said housing.
 32. The apparatusaccording to claim 31 wherein said first and second end caps are appliedto said first and second ends of said housing by a means selected fromthe group consisting of welding and gluing.
 33. A diffusion/filtrationapparatus comprising:a) housing means, said housing means defining alongitudinally extending internal chamber including a first end and asecond end; b) a bundle of semi-permeable hollow fibers disposed withinsaid internal chamber, said hollow fibers extending longitudinally fromsaid first end of said housing to said second end of said housing, saidhollow fibers having an outer surface, and a first end and a second endcorresponding to said first end and said second end of said internalchamber; c) end wall means supporting said first and second ends of saidhollow fibers within said internal chamber so as to sealingly separatesaid first and second ends of said hollow fiber from said outer surfaceof said hollow fiber between said first and second ends thereof; d)first inlet means for the introduction of a fluid into said first end ofsaid housing means; e) first outlet means for the evacuation of a fluidfrom said second end of said housing means; f) second outlet means forthe evacuation of a fluid from said internal chamber at a locationbetween said first and second end of said housing means; g) at least onering member disposed between said end wall means and said housing meansat one of said first and second ends of said internal chamber, said ringmember having a shape corresponding to said housing and defining acavity between said ring member and said hollow fibers, the coefficientof adhesion between said end wall means and said ring member being lowerthan the coefficient of adhesion between said end wall means and saidhousing, whereby the structural integrity of said housing means and theseal between said ends of said hollow fibers and said outer surface ofsaid hollow fibers is enhanced; and h) support means integral for saidhousing, said support means comprising longitudinally extending tonguemeans extending from a predetermined location on said housing meansbetween said first and second ends thereof into said end wall means forlongitudinally supporting said end wall means.
 34. The apparatusaccording to claim 33 including ring support means for supporting saidring member from said housing.
 35. The apparatus according to claim 34wherein said ring support means comprises an annular groove in saidhousing, said ring member being longitudinally engaged in said annulargroove.
 36. The apparatus according to claim 33 wherein said first inletmeans is defined by a first end cap covering said first end of saidhousing and said first outlet means is defined by a second end capcovering, said second end of said housing.
 37. The apparatus accordingto claim 36 wherein said first and second end caps are applied to saidfirst and second ends of said housing by a means selected from the groupconsisting of welding and gluing.
 38. The apparatus according to claim33 including at least one sealing ring interposed between said end walland said first inlet means.
 39. A diffusion/filtration apparatuscomprising:a) housing means, said housing means defining alongitudinally extending internal chamber including a first end and asecond end; b) a bundle of semi-permeable hollow fibers disposed withinsaid internal chamber, said hollow fibers extending longitudinally fromsaid first end of said housing to said second end of said housing, saidhollow fibers having an outer surface, and a first end and a second endcorresponding to said first end and said second end of said internalchamber; c) end wall means supporting said first and second ends of saidhollow fibers within said internal chamber so as to sealingly separatesaid first and second ends of said hollow fiber from said outer surfaceof said hollow fiber between said first and second ends thereof; d)first inlet means for the introduction of a fluid into said first end ofsaid housing means; e) first outlet means for the evacuation of a fluidfrom said second end of said housing means; f) second outlet means forthe evacuation of a fluid from said internal chamber at a locationbetween said first and second end of said housing means; g) at least onering member disposed between said end wall means and said housing meansat one of said first and second ends of said internal chamber, said ringmember having a shape corresponding to said housing and defining acavity between said ring member and said hollow fibers, the coefficientof adhesion between said end wall means and said ring member being lowerthan the coefficient of adhesion between said end wall means and saidhousing, whereby the structural integrity of said housing means and theseal between said ends of said hollow fibers and said outer surface ofsaid hollow fibers is enhanced; and h) support means within said cavityfor longitudinally supporting said end wall means.
 40. The apparatusaccording to claim 39 wherein said ring member includes an inner surfaceand an outer surface, and wherein said support means comprise a flangeextending inwardly from said inner surface of said ring member.
 41. Theapparatus according to claim 40 wherein said flange extends inwardly asto said bundle of hollow fibers so as to provide support therefor. 42.The apparatus according to claim 39 wherein said support means areintegral with said housing.
 43. The apparatus according to claim 42wherein said support means comprise longitudinally extending tonguemeans extending from a predetermined location on said housing meansbetween said first and second ends thereof into said end wall means. 44.The apparatus according to claim 39 wherein said first inlet means isdefined by a first end cap covering said first end of said housing andsaid first outlet means is defined by a second end cap covering saidsecond end of said housing.
 45. The apparatus according to claim 44wherein said first and second end caps are applied to said first andsecond ends of said housing by a means selected from the groupconsisting of welding and gluing.
 46. The apparatus according to claim39 including at least one sealing ring interposed between said end walland said first inlet means.
 47. A diffusion/filtration apparatuscomprising:a) housing means, said housing means defining alongitudinally extending internal chamber including a first end and asecond end; b) a bundle of semi-permeable hollow fibers disposed withinsaid internal chamber, said hollow fibers extending longitudinally fromsaid first end of said housing to said second end of said housing, saidhollow fibers having an outer surface, and a first end and a second endcorresponding to said first end and said second end of said internalchamber; c) end wall means supporting said first and second ends of saidhollow fibers within said internal chamber so as to sealingly separatesaid first and second ends of said hollow fiber from said outer surfaceof said hollow fiber between said first and second ends thereof; d)first inlet means for the introduction of a fluid into said first end ofsaid housing means; e) first outlet means for the evacuation of a fluidfrom said second end of said housing means; wherein said support meanscomprise a flange extending inwardly from said inner surface of saidring member; f) second outlet means for the evacuation of a fluid fromsaid internal chamber at a location between said first and second end ofsaid housing means; and g) at least one ring member disposed betweensaid end wall means and said housing means at one of said first andsecond ends of said internal chamber, said ring member having a shapecorresponding to said housing and defining a cavity between said ringmember and said hollow fibers, said ring member being in direct contactwith said housing means, and said end wall means at said one of saidfirst and second ends of said internal chamber having a first portion incontact with said ring member comprising a substantial portion of saidend wall means, and having a second portion comprising a minor portionof said end wall means engaging said housing means between said one ofsaid first and second ends of said internal chamber and said at leastone ring member, said end wall means including slot means therein at alocation adjacent to said second portion of said end wall means, thecoefficient of adhesion between said first portion of said end wallmeans and said ring member being lower than the coefficient of adhesionbetween said second portion of said end wall means and said housing,whereby the structural integrity of said housing means and the sealbetween said ends of said hollow fibers and said outer surface of saidhollow fibers is enhanced, while at the same time a seal is providedbetween said at least one of said first and second ends of said internalchamber and said internal chamber.
 48. The apparatus according to claim47 including support means within said cavity for longitudinallysupporting said end wall means.
 49. The apparatus according to claim 48wherein said ring member includes a inner surface and an outer surface,and
 50. The apparatus according to claim 47 including at least onesealing ring interposed between said end wall and said first inletmeans.